What is supposed way to know that error have been fixed?
There is nothing to fix as error is from parser because input is missing sync, so it skip all bytes until it finds missing sync bytes. Everything points that first frame from file is trimmed.

-xerror will abort when first error is encountered. There is no way that seeking will magically avoid error. Perhaps you need to use -ss 1 as input option instead, but still it can not guarantee that error should not happen, because it needs to give somehow frame with missing sync to be able to skip it.